Learning bird calls is like an outdoor superpower but I think it'd be a little better if you could focus the user on songs they are going to hear in their area.
Still, it's a great idea. Just listening to a blackbird (Turdus merula) or song thrush (Turdus philomelos) singing on a nice Spring evening is life-affirming all by itself.
There's a reason the eBird quizzes let you specify a time and location (and a few other parameters). All that being said it's a super cool game and makes me want to take another birding trip!
Edit: just as an FYI for Americans using this: it doesn't look like it's using the names I'm familiar with always as an American (which I think are the ABA names). Americans will refer to these birds differently sometimes, the example I found was it mentioned a "common starling" but in the US I always see that bird called "European starling"